Texaco already has an alliance with Shell, the U.S. subsidiary of Royal Dutch/Shell Group. Texaco and Chevron also have overlapping operations on the West Coast.

And there were also issues of control, namely that Chevron chairman and chief executive Kenneth T. Derr wanted it, and Texaco chairman and chief executive Peter Bijur was apparently unwilling to cede it.

News of a stalemate between Chevron and Texaco comes just six days after shareholders of Exxon and Mobil voted to approve their $82 billion merger.